/* Fundamentals course widgets. Prefix fu-. Uses book.css tokens and learn.css lab shell. */

/* Two waves */
.fu-legend{display:flex;flex-wrap:wrap;gap:16px;font-size:12px;color:var(--muted);margin:-4px 0 0}
.fu-legend span{display:flex;align-items:center;gap:6px}
.fu-legend span:before{content:'';width:18px;height:4px;border-radius:2px;background:var(--c)}

/* Octave ladder */
.fu-ladder{display:flex;flex-direction:column;gap:8px}
.fu-rung{display:grid;grid-template-columns:52px minmax(0,1fr) auto;gap:14px;align-items:center;text-align:left;background:#fffdf6;border:1px solid #e3dfcf;border-left:6px solid var(--c);min-height:56px}
.fu-rung strong{font:500 22px var(--serif);color:var(--c)}
.fu-rung svg{width:100%;height:28px;stroke:var(--c);stroke-width:2.4}
.fu-rung span{font-size:12px;font-weight:500;color:var(--muted);white-space:nowrap}
.fu-rung.on{background:color-mix(in srgb,var(--c) 16%,#fffdf6);transform:translateX(4px)}

/* Pentatonic */
.fu-penta .kb-key.white:not(.lit){background:#efece0;color:#b8b6a8}
.fu-penta .kb-key.black:not(.lit){background:#7c847d}
.fu-pulse{width:16px;height:16px;border-radius:50%;background:#e1ddcc;transition:background .12s,transform .12s}
.fu-pulse.on{background:var(--gold);transform:scale(1.25)}

/* Twelve notes */
.fu-circles{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:6px}
.fu-circle{aspect-ratio:1;min-height:44px;padding:0;border-radius:50%;background:var(--c);border:0;color:#fffaf0;font:600 13px/1.1 var(--body);display:grid;place-items:center;box-shadow:0 4px 0 color-mix(in srgb,var(--c) 70%,#000 14%);transition:transform .08s}
.fu-circle.black{box-shadow:0 4px 0 #33413b;font-size:10px}
.fu-circle:hover{background:var(--c);filter:brightness(1.06)}
.fu-circle.on{transform:translateY(-6px) scale(1.08)}
.fu-letters{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:6px}
.fu-letters button{font:500 22px var(--serif);padding:6px 0}
.fu-letters button[aria-pressed=true]{background:var(--teal);border-color:var(--teal);color:#fffdf4}
.fu-acc button{font-size:15px}
.fu-target{margin:0;min-height:56px;font-size:52px!important}

/* Scale hops */
.fu-kbwrap{position:relative;display:flex;flex-direction:column}
.fu-hops{width:100%;height:64px;display:block;overflow:visible;fill:none}
.fu-hops path{stroke-width:3;stroke-linecap:round;transition:stroke-width .1s}
.fu-hops path.big{stroke:var(--teal)}
.fu-hops path.small{stroke:var(--rust);stroke-dasharray:1 0}
.fu-hops path.on{stroke:var(--gold);stroke-width:6}
.fu-hops text{font:600 11px var(--body);text-anchor:middle;stroke:none}
.fu-hops text.big{fill:var(--teal)}
.fu-hops text.small{fill:var(--rust)}
.lab .note-chip{display:inline-block;min-width:30px;padding:0 8px;border-radius:13px;color:#fffaf0;font-weight:600;font-size:14px;text-align:center;line-height:26px}
.fu-chips{margin:0;font-size:14px;line-height:2.1}
.fu-hopbtns button{min-width:160px;min-height:56px;font-size:16px}
.fu-hopbtns .fu-big{background:var(--teal-soft);border-color:#a4c2ae;color:var(--teal)}
.fu-hopbtns .fu-small{background:#f6e2d9;border-color:#e0b8a8;color:var(--rust)}
.fu-moved .note-chip{outline:3px solid var(--gold);outline-offset:1px}

/* Chord stack */
.fu-chordtop{display:grid;grid-template-columns:150px minmax(0,1fr);gap:22px;align-items:center}
.fu-stack{--h:15px;position:relative;height:calc(var(--rows) * var(--h) + 44px);background:repeating-linear-gradient(to top,#f1eee2 0 1px,transparent 1px var(--h));background-position:0 22px;border-radius:12px}
.fu-dot{position:absolute;left:50%;bottom:calc(var(--y) * var(--h) + 2px);width:44px;height:40px;margin-left:-22px;border-radius:50%;background:var(--c);color:#fffaf0;display:grid;place-items:center;box-shadow:0 4px 0 color-mix(in srgb,var(--c) 70%,#000 14%);transition:bottom .35s cubic-bezier(.3,1.4,.5,1),transform .1s}
.fu-dot b{font:500 16px var(--serif)}
.fu-dot small{position:absolute;left:52px;white-space:nowrap;font-size:11px;font-weight:600;color:var(--muted)}
.fu-dot.on{transform:scale(1.18)}
.fu-chordname{font:500 34px var(--serif);letter-spacing:-.03em;margin:0 0 6px}
.fu-chordname small{display:block;font:600 13px var(--body);color:var(--muted);letter-spacing:0;margin-top:4px}
.fu-chordsays{margin:0;font-size:15px;line-height:1.9}

/* Ear game and twins */
.fu-ear button,.fu-twins button{flex:1;min-width:200px;min-height:64px;font-size:16px;border:2px solid var(--c);color:var(--c);background:color-mix(in srgb,var(--c) 8%,var(--sheet))}
.fu-ear button:hover,.fu-twins button:hover{background:color-mix(in srgb,var(--c) 16%,var(--sheet))}

/* Chords of a key */
.fu-cards{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:8px}
.fu-card{display:flex;flex-direction:column;align-items:center;gap:6px;padding:12px 4px;min-height:132px;border:2px solid color-mix(in srgb,var(--q) 55%,transparent);background:color-mix(in srgb,var(--q) 7%,var(--sheet));border-radius:14px}
.fu-card strong{font:500 22px var(--serif);color:var(--q)}
.fu-card span{font-size:13px;line-height:1.35;color:var(--ink)}
.fu-card small{font-size:10px;font-weight:600;color:var(--q);text-transform:uppercase;letter-spacing:.04em}
.fu-card.on,.fu-card:hover{background:color-mix(in srgb,var(--q) 18%,var(--sheet))}
.fu-card.on{transform:translateY(-3px);box-shadow:0 6px 0 color-mix(in srgb,var(--q) 40%,transparent)}
.fu-slots{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}
.fu-slot{display:flex;flex-direction:column;align-items:center;gap:2px;min-height:96px;border:2px solid color-mix(in srgb,var(--q) 50%,transparent);background:color-mix(in srgb,var(--q) 8%,var(--sheet));border-radius:14px}
.fu-slot small{font-size:10px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}
.fu-slot strong{font:500 30px var(--serif);color:var(--q)}
.fu-slot span{font-size:13px}
.fu-slot.sel{border-style:dashed;border-color:var(--ink)}
.fu-slot.now{outline:4px solid var(--gold);outline-offset:2px}
.fu-palette{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:6px}
.fu-palette button{font:500 18px var(--serif);padding:6px 0;color:var(--q);border-color:color-mix(in srgb,var(--q) 45%,transparent)}
.fu-palette button[aria-pressed=true]{background:var(--q);color:#fffaf0}

/* Keys */
.fu-keyhead{display:grid;grid-template-columns:64px minmax(0,1fr) 64px;align-items:center;gap:10px}
.fu-arrow{min-height:56px;font-size:20px}
.fu-keyname{margin:0;font-size:40px!important}
.kb-key.fu-home:after{content:'';position:absolute;left:50%;top:10px;width:18px;height:18px;margin-left:-9px;border-radius:50%;border:3px solid var(--gold);box-sizing:border-box}
.kb-key.black.fu-home:after{top:8px}
.fu-moves{margin:0;min-height:48px;font-size:15px;line-height:1.9}
.fu-home-btns button{flex:1;min-width:190px}

/* Inversions */
.fu-inv{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}
.fu-col{display:flex;flex-direction:column;gap:6px;align-items:stretch;padding:8px;border-radius:14px;transition:background .1s}
.fu-col>strong{text-align:center;font:500 24px var(--serif)}
.fu-col.now{background:#f7ecd0}
.fu-col button{display:flex;flex-direction:column;align-items:center;gap:2px;padding:6px 4px;min-height:84px}
.fu-col button[aria-pressed=true]{background:var(--teal-soft);border-color:var(--teal);box-shadow:inset 0 0 0 1px var(--teal)}
.fu-col i{font:normal 600 13px/1.2 var(--body);color:var(--c)}
.fu-meter{height:10px;border-radius:5px;background:#ece9dc;overflow:hidden}
.fu-meter span{display:block;height:100%;width:calc(var(--f,0) * 100%);background:linear-gradient(90deg,var(--teal),var(--gold),var(--rust));transition:width .3s}


.fu-row .lab-choices{flex:1 1 300px}
.fu-row .lab-choices button{white-space:nowrap}

/* Instruments */
.fu-families{flex-wrap:wrap}
.fu-families button{flex:1 1 auto!important}
.fu-instruments{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px}
.fu-inst{display:flex;flex-direction:column;align-items:flex-start;gap:4px;text-align:left;min-height:78px;padding:12px 16px;border:2px solid color-mix(in srgb,var(--c) 45%,transparent);background:color-mix(in srgb,var(--c) 7%,var(--sheet));border-radius:16px}
.fu-inst strong{font:500 20px var(--serif);color:var(--c)}
.fu-inst small{font-size:12px;color:var(--muted);font-weight:600}
.fu-inst:hover{background:color-mix(in srgb,var(--c) 14%,var(--sheet))}
.fu-inst.on{background:color-mix(in srgb,var(--c) 20%,var(--sheet));box-shadow:0 5px 0 color-mix(in srgb,var(--c) 45%,transparent);transform:translateY(-2px)}
.fu-inst.right{background:var(--teal-soft);border-color:var(--teal)}
.fu-inst.not{opacity:.55}
.fu-register{position:relative;height:34px;border-radius:17px;background:linear-gradient(90deg,#e7e1cf,#f5f1e4);overflow:hidden}
.fu-reg-band{position:absolute;top:0;bottom:0;left:0;width:0;opacity:.35;transition:left .3s,width .3s}
.fu-reg-now{position:absolute;top:7px;width:20px;height:20px;margin-left:-10px;border-radius:50%;opacity:0;transition:left .08s}
.fu-register small{position:absolute;top:9px;font-size:11px;font-weight:600;color:var(--muted)}
.fu-register .lo{left:14px}.fu-register .hi{right:14px}
.fu-says{margin:0;font-size:15px;min-height:26px}
.fu-bows{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.fu-bowcol{display:flex;flex-direction:column;gap:8px}
.fu-bowcol>strong{font:500 22px var(--serif)}
.fu-bow{min-height:60px;font-size:16px}
.fu-bow.bowed{border-color:#e0b8a8;color:var(--rust);background:#fbeee8}
.fu-bow.plucked{border-color:#a4c2ae;color:var(--teal);background:var(--teal-soft)}
.fu-bow.on{outline:3px solid var(--gold);outline-offset:2px}

@media(max-width:700px){
  .fu-circles{grid-template-columns:repeat(6,minmax(0,1fr))}
  .fu-cards{grid-template-columns:repeat(4,minmax(0,1fr))}
  .fu-chordtop{grid-template-columns:120px minmax(0,1fr);gap:14px}
  .fu-chordname{font-size:28px}
  .fu-hops text{display:none}
  .fu-palette button{font-size:15px}
}
@media(max-width:480px){
  .fu-inv{grid-template-columns:repeat(2,minmax(0,1fr))}
  .fu-slots{grid-template-columns:repeat(2,minmax(0,1fr))}
  .fu-rung{grid-template-columns:44px minmax(0,1fr)}
  .fu-rung span{grid-column:1/-1;margin-top:-10px}
  .fu-chordtop{grid-template-columns:1fr}
  .fu-stack{max-width:200px;margin:auto;width:100%}
  .fu-letters button{font-size:18px}
  .fu-bows{grid-template-columns:1fr}
  .fu-instruments{grid-template-columns:1fr 1fr}
}
@media(prefers-reduced-motion:reduce){
  .fu-dot,.fu-rung,.fu-circle,.fu-card,.fu-pulse,.fu-meter span,.fu-reg-band,.fu-reg-now,.fu-inst{transition:none}
}